OPTN/SRTR 2018 Annual Data Report: Liver

Intraoperative kidney replacement therapy in acute liver failure

Paediatric acute liver failure (PALF) is often characterised by its rapidity of onset and potential for significant morbidity and even mortality. Patients often develop multiorgan dysfunction/failure, including severe acute kidney injury (AKI). Whilst the management of PALF focuses on complications of hepatic dysfunction, the associated kidney impairment can significantly affect patient outcomes. Severe AKI requiring continuous kidney replacement therapy (CKRT) is a common complication of both PALF and liver transplantation. In both scenarios, the need for CKRT is a poor prognostic indicator. In adults, AKI has been shown to complicate ALF in 25-50% of cases. In PALF, the incidence of AKI is often higher compared to other critically ill paediatric ICU populations, with reports of up to 40% in some observational studies. Furthermore, those presenting with AKI regularly have a more severe grade of PALF at presentation. Observational studies in the paediatric population corroborate this, though data are not as robust-mainly reflecting single-centre cohorts. Perioperative benefits of CKRT include helping to clear water-soluble toxins such as ammonia, balancing electrolytes, preventing fluid overload, and managing raised intracranial pressure. As liver transplantation often takes 6-10 h, it is proposed that these benefits could be extended to the intraoperative period, avoiding any hiatus. Intraoperative CKRT (IoCKRT) has been shown to be practicable, safe and may help sicker recipients tolerate the operation with outcomes analogous with less ill patients not requiring IoCKRT. Here, we provide a comprehensive guide describing the rationale, practicalities, and current evidence base surrounding IoCKRT during transplantation in the paediatric population.

No Improvement in Intention-to-treat Survival and Increasing Liver Nonutilization Rate During the MELD Era

BACKGROUND

Although post liver transplant survival rates have significantly improved during the past 2-3 decades, the trend in intention-to-treat (ITT) survival (survival from waitlist addition) has not been well studied.

METHODS

We conducted a retrospective analysis of Scientific Registry of Transplant Recipients data to determine the trend in ITT survival in liver transplant candidates. Adult (age ≧ 18 y) patients who were on the waitlist between the time period of March 1, 2002, to December 31, 2019 (n = 200 816) and deceased liver donors that were registered between the same time period (n = 152 593) were analyzed.

RESULTS

We found a constant increase in posttransplant survival rates; however, the ITT survival rates showed no statistically significant improvement through the study period. We observed significant linear increase in waitlist dropout rates over time. We also observed linear increase in liver nonutilization rate in both entire cases and brain-dead cases. Donor risk index increased significantly over the years; however, it was mostly driven by increase in donation after circulatory death cases; without donation after circulatory death cases, donor risk index was stable throughout the 17 y we observed.

CONCLUSIONS

The reason of the increased liver nonutilization rate is unclear; however, it is possible that reluctance to use high-risk organ to maintain better posttransplant outcomes contributed to this increase, which also could have led to increase in waitlist dropout rates and no improvements in ITT survival. Further investigation is warranted on the increased nonutilization rates to improve over all contribution of liver transplant to patient care.

Antiplatelet agent for the prevention of late hepatic vascular complications in living donor-dominant liver transplant population

BACKGROUND

Evidence for the long-term use of antiplatelet drugs to prevent hepatic vascular complications (HVC) is scarce in liver transplantation (LT).

METHODS

From national claim data, LT recipients (about 80 % of living donor LT [LDLT]) without graft loss, HVC, or cardiovascular events within 1 year, were classified into those who took antiplatelets for ≥1 year (n = 1744) and for <1 year (n = 1975). Outcomes were compared after the 1-postoperative year index time point.

RESULTS

During a mean follow up of 4.5 years, the risk of graft loss was similar between the groups (aHR 1.16, P = 0.23). However, ≥1-year antiplatelet therapy was associated with a higher risk of graft loss after 3 years (aHR 2.19, P < 0.01). HVC (aHR 0.94, P = 0.87) and major adverse cardiac events (aHR 1.20, P = 0.46) did not correlate with antiplatelet therapy for both groups. In contrast, ≥1-year antiplatelet therapy showed a significantly higher risk of severe bleeding compared to <1-year antiplatelet therapy (aHR 2.24, P < 0.01). This trend was similar in the LDLT subgroup. In our cohort, antiplatelet therapy for ≥1 year did not improve graft survival or HVC; however, it increased the risk of severe bleeding.

CONCLUSION

We recommend against antiplatelet therapy for more than 1 year in clinically stable LT recipients.

Variation in intention-to-treat survival by MELD subtypes: all models created for end-stage liver disease are not equal

BACKGROUND & AIMS

Kidney dysfunction is a major determinant of prognosis in patients with decompensated cirrhosis awaiting transplantation. We hypothesized that for identical MELD scores at listing, outcomes before and after liver transplantation may vary if the predominant driver of the MELD score is serum creatinine versus serum bilirubin or INR.

METHODS

We evaluated all adult patients registered for liver transplantation (LT) between 2016 - 2020 and excluded patients receiving MELD exceptions or undergoing dual organ transplantation. Using K-Means clustering analysis, we classified each patient as MELD-Br, MELD-INR or MELD-Cr depending on the dominant variable for their MELD score. The primary outcome was intent-to-treat survival, defined as survival within 1 year from listing with or without LT.

RESULTS

MELD scores of LT waitlist registrants clustered into 3 subtypes: MELD-Br (n=13,658), MELD-INR (n=13,809), and MELD-Cr (n=12,412). One-year ITT survival was 78% (MELD-Br), 75% (MELD-INR), and 65% (MELD-Cr), p<0.01. ITT survival was lower for each MELD subtype for females compared to males (e.g. MELD Cr 63% females vs 67% males, p<0.0001). MELD-Cr subtype had the highest MELD at listing (MELD Cr 23.4 vs MELD-Br 19.2 vs MELD INR 21.0) and the largest decline in MELD over 3 months (23% vs. 12% vs 21%). In adjusted analyses including MELD Na, MELD-Cr compared to the other subtypes was associated with higher WL mortality (HR 1.339, 95% CI 1.279-1.402) and lower LT rates (HR 0.688, 95% CI 0.664-0.713).

CONCLUSIONS

For equivalent listing practices, registrants with MELD-Cr subtype have lower ITT survival. MELD subtype may serve as a more sophisticated variable for dynamic assessment of risk of mortality, to inform models for organ allocation.

IMPACT AND IMPLICATIONS

The MELD score is an excellent predictor of waitlist mortality; however, our work highlights that the driver of a patient's score MELD score matters and particularly those driven by elevated creatinine have a lower 1-year ITT mortality. The 1-year ITT mortality is also lower for women compared to men within the Cr-dominant subtype. These results are important for physicians and patients undergoing LT evaluation as creatinine may serve as a marker of prognosis and even if the creatinine improves the prognosis remains poor, necessitating discussion about alternative pathways for transplant. Our work also highlights that the type of kidney injury matters, in that those AKI were more likely to die or remain on the waitlist compared to those with CKD within the creatinine dominant subtype.

Risk factors associated with blood transfusion in liver transplantation

To explore preoperative and operative risk factors for red blood cell (RBC) transfusion requirements during liver transplantation (LT) and up to 24 h afterwards. We evaluated the associations between risk factors and units of RBC transfused in 176 LT patients using a log-binomial regression model. Relative risk was adjusted for age, sex, and the model for end-stage liver disease score (MELD) (adjustment 1) and baseline hemoglobin concentration (adjustment 2). Forty-six patients (26.14%) did not receive transfusion. Grafts from cardiac-death donors were used in 32.61% and 31.54% of non-transfused and transfused patients, respectively. The transfused group required more reoperation for bleeding (P = 0.035), longer mechanical ventilation after LT (P < 0.001), and longer ICU length of stay (P < 0.001). MELD and hemoglobin concentrations determined RBC requirements. For each unit of increase in the MELD score, 2% more RBC units were transfused, and non-transfusion was 0.83-fold less likely. For each 10-g/L higher hemoglobin concentration at baseline, 16% less RBC transfused, and non-transfusion was 1.95-fold more likely. Ascites was associated with 26% more RBC transfusions. With an increase of 2 mm from the baseline in the A10FIBTEM measurement of maximum clot firmness, non-transfusion was 1.14-fold more likely. A 10-min longer cold ischemia time was associated with 1% more RBC units transfused, and the presence of post-reperfusion syndrome with 45% more RBC units. We conclude that preoperative correction of anemia should be included in LT. An intervention to prevent severe hypotension and fibrinolysis during graft reperfusion should be explored.Trial register: European Clinical Trials Database (EudraCT 2018-002,510-13) and ClinicalTrials.gov (NCT01539057).

Head and neck squamous cell carcinoma (HNSCC) in solid organ transplant recipients - Results from the scientific registry of transplant recipients (SRTR) database

BACKGROUND

Solid organ transplant recipients have an elevated risk of cancer following organ transplantation than the age-adjusted general population. We assessed incidence of head and neck squamous cell carcinoma (HNSCC) in heart, lung, and liver recipients.

BASIC PROCEDURES/METHODS

This retrospective cohort study included 124,966 patients from the United States Scientific Registry of Transplant Recipients (SRTR) database who received heart, lung, or liver transplantation between 1991 and 2010. Follow-up data were available until 2018. Patients with prevalent HNSCC at transplantation were excluded. Incident cases of HNSCC post organ transplantation were identified, and incidence rates (per 100,000 person-years) were reported by gender, race, organ type, year and age at organ transplantation.

MAIN FINDINGS

The majority of patients received liver transplantation (58.64 %), followed by heart (28.64 %), and lung (12.72 %) transplantation. During follow-up, 4.14 % patients developed HNSCC. Overall incidence rate of HNSCC was 426.76 per 100,000 person-years. Male recipients had a higher HNSCC incidence rate than female recipients (571.8 and 177.0 per 100,000 person-years, respectively). Lung recipients had the highest overall HNSCC incidence rate (1273.6 per 100,000 person-years), followed by heart (644.2 per 100,000 person-years), and liver recipients (207.1 per 100,000 person-years). Overall, an increase in HNSCC incidence rate was observed with increase in age at organ transplantation. An increase in incidence rates of HNSCC over time was observed in lung recipients; however, incidence rates decreased over time in heart recipients.

CONCLUSION

Solid organ transplant recipients have a high incidence of HNSCC following organ transplantation, and the incidence varies by type of organ received.

Hernia Correction After Liver Transplantation Using Nonvascularized Fascia

Background

Liver transplantation is an increasingly frequent surgical procedure, with elevated rates of postoperative incisional hernias ranging from 5% to 46%. There are numerous known risk factors for incisional hernia, including the type of incision, patient sex, and presence of comorbidities such as diabetes, ascites, older age, and the use of steroids. Most studies on the treatment of incisional hernias in patients who have undergone liver transplantation have shown consistently high rates of complications. Consequently, we propose the use of nonvascular fascia for the symptomatic treatment of incisional hernias in patients with concomitant liver transplantation.

Methods

We performed our new technique on 8 patients, who had previously undergone liver transplantation, between January 2019 and January 2023. The patients were examined using imaging techniques during the follow-up period.

Results

Of the 8 patients, 7 were liver transplant recipients and 1 was a combined liver-kidney transplant patient. The median donor age was 57 y (5-66 y), whereas the mean recipient age was 58 y (31-66 y). The median patient height and weight were 163 cm (117-185 cm) and 76 kg (17-104 kg), respectively. Immunosuppression did not change in fascia recipients. The median time between transplantation and hernia repair surgery was 41 mo (5-116 mo). The sizes of the aponeurotic defects varied from 6 × 6 to 25 × 20 cm. Two patients experienced complications: one experienced bulging that required reintervention and the other experienced surgical site seroma. There was no mortality related to the use of the technique, and none were reported during follow-up.

Conclusions

With its promising results, nonvascularized fascial transplantation can be a successful treatment for incisional hernias in patients who had previously received a liver transplant.

Advancements in Predictive Tools for Primary Graft Dysfunction in Liver Transplantation: A Comprehensive Review

Orthotopic liver transplantation stands as the sole curative solution for end-stage liver disease. Nevertheless, the discrepancy between the demand and supply of grafts in transplant medicine greatly limits the success of this treatment. The increasing global shortage of organs necessitates the utilization of extended criteria donors (ECD) for liver transplantation, thereby increasing the risk of primary graft dysfunction (PGD). Primary graft dysfunction (PGD) encompasses early allograft dysfunction (EAD) and the more severe primary nonfunction (PNF), both of which stem from ischemia-reperfusion injury (IRI) and mitochondrial damage. Currently, the only effective treatment for PNF is secondary transplantation within the initial post-transplant week, and the occurrence of EAD suggests an elevated, albeit still uncertain, likelihood of retransplantation urgency. Nonetheless, the ongoing exploration of novel IRI mitigation strategies offers hope for future improvements in PGD outcomes. Establishing an intuitive and reliable tool to predict upcoming graft dysfunction is vital for early identification of high-risk patients and for making informed retransplantation decisions. Accurate diagnostics for PNF and EAD constitute essential initial steps in implementing future mitigation strategies. Recently, novel methods for PNF prediction have been developed, and several models for EAD assessments have been introduced. Here, we provide an overview of the currently scrutinized predictive tools for PNF and EAD evaluation strategies, accompanied by recommendations for future studies.

Expanding the liver donor pool worldwide with hepatitis C infected livers, is it the time?

Liver transplantation (LT) provides a life-saving option for cirrhotic patients with complications and hepatocellular carcinoma. Despite the increasing number of liver transplants performed each year, the number of LT candidates on the waitlist remains unchanged due to an imbalance between donor organ supply and the demand which increases the waitlist time and mortality. Living donor liver transplant had a great role in increasing the donor pool and shortened waitlist time for LT candidates. Nevertheless, further strategies can be implemented to increase the pool of potential donors in deceased donor LT, such as reducing the rate of organ discards. Utilizing hepatitis C virus (HCV) seropositive liver grafts is one of the expanded donor organ criteria. A yearly increase of hundreds of transplants is anticipated as a result of maximizing the utilization of HCV-positive organs for HCV-negative recipients. Direct-acting antiviral therapy's efficacy has revolutionized the treatment of HCV infection and the use of HCV-seropositive donors in transplantation. The American Society of Transplantation advises against performing transplants from HCV-infected liver donors (D+) into HCV-negative recipient (R-) unless under Institutional Review Board-approved study rules and with full informed consent of the knowledge gaps associated with such transplants. Proper selection of patients to be transplanted with HCV-infected grafts and confirming their access to direct-acting antivirals if needed is important. National and international consensuses are needed to regulate this process to ensure the maximum benefit and the least adverse events.

Development of a nomogram for predicting liver transplantation prognosis in hepatocellular carcinoma

BACKGROUND

At present, liver transplantation (LT) is one of the best treatments for hepatocellular carcinoma (HCC). Accurately predicting the survival status after LT can significantly improve the survival rate after LT, and ensure the best way to make rational use of liver organs.

AIM

To develop a model for predicting prognosis after LT in patients with HCC.

METHODS

Clinical data and follow-up information of 160 patients with HCC who underwent LT were collected and evaluated. The expression levels of alpha-fetoprotein (AFP), des-gamma-carboxy prothrombin, Golgi protein 73, cytokeratin-18 epitopes M30 and M65 were measured using a fully automated chemiluminescence analyzer. The best cutoff value of biomarkers was determined using the Youden index. Cox regression analysis was used to identify the independent risk factors. A forest model was constructed using the random forest method. We evaluated the accuracy of the nomogram using the area under the curve, using the calibration curve to assess consistency. A decision curve analysis (DCA) was used to evaluate the clinical utility of the nomograms.

RESULTS

The total tumor diameter (TTD), vascular invasion (VI), AFP, and cytokeratin-18 epitopes M30 (CK18-M30) were identified as important risk factors for outcome after LT. The nomogram had a higher predictive accuracy than the Milan, University of California, San Francisco, and Hangzhou criteria. The calibration curve analyses indicated a good fit. The survival and recurrence-free survival (RFS) of high-risk groups were significantly lower than those of low- and middle-risk groups (P < 0.001). The DCA shows that the model has better clinical practicability.

CONCLUSION

The study developed a predictive nomogram based on TTD, VI, AFP, and CK18-M30 that could accurately predict overall survival and RFS after LT. It can screen for patients with better postoperative prognosis, and improve long-term survival for LT patients.

The role of cold ischemia time and hypothermic perfusion in predicting early hepatocellular carcinoma recurrences after liver transplantation

AIM

The aim of the study was to identify predictors of early tumor recurrence in patients with hepatocellular carcinoma (HCC) after liver transplantation (LT).

METHODS

Retrospective cohort study in 237 consecutive liver recipients with HCC between 2016 and 2021. Multivariate logistic analysis was performed to identify predictors of early HCC recurrences. The impact of hypothermic-oxygenated perfusion (HOPE) on outcome was analyzed after propensity score weighting.

RESULTS

Early recurrences were observed in 15 cases. Microvascular invasion (OR 3.737, 95% CI 1.246-11.206, p = 0.019) and cold ischemia time (OR 1.155, 95% CI 1.001-1.333, p = 0.049) were independently associated with a lower risk of HCC recurrences. After balancing for relevant variables, patients in the HOPE group had lower rates of tumor recurrence (weighted OR 0.126, 95% CI 0.016-0.989, p = 0.049) and higher recurrence free survival (weighted HR 0.132, 95% CI 0.017-0.999, p = 0.050).

CONCLUSION

Reducing cold ischemia time and graft perfusion with HOPE can lead to lower rates of early HCC recurrences and higher recurrence-free survival.

LIVER RETRANSPLANTATION: PROGNOSTIC SCORES AND RESULTS IN THE STATE OF PARANÁ

BACKGROUND

Hepatic retransplantation is associated with higher morbidity and mortality when compared to primary transplantation. Given the scarcity of organs and the need for efficient allocation, evaluating parameters that can predict post-retransplant survival is crucial.

AIMS

This study aimed to analyze prognostic scores and outcomes of hepatic retransplantation.

METHODS

Data on primary transplants and retransplants carried out in the state of Paraná in 2019 and 2020 were analyzed. The two groups were compared based on 30-day survival and the main prognostic scores of the donor and recipient, namely Model for End-Stage Liver Disease (MELD), MELD-albumin (MELD-a), Donor MELD (D-MELD), Survival Outcomes Following Liver Transplantation (SOFT), Preallocation Score to Predict Survival Outcomes Following Liver Transplantation (P-SOFT), and Balance of Risk (BAR).

RESULTS

A total of 425 primary transplants and 30 retransplants were included in the study. The main etiology of hepatopathy in primary transplantation was ethylism (n=140; 31.0%), and the main reasons for retransplantation were primary graft dysfunction (n=10; 33.3%) and hepatic artery thrombosis (n=8; 26.2%). The 30-day survival rate was higher in primary transplants than in retransplants (80.5% vs. 36.7%, p=0.001). Prognostic scores were higher in retransplants than in primary transplants: MELD 30.6 vs. 20.7 (p=0.001); MELD-a 31.5 vs. 23.5 (p=0.001); D-MELD 1234.4 vs. 834.0 (p=0.034); SOFT 22.3 vs. 8.2 (p=0.001); P-SOFT 22.2 vs. 7.8 (p=0.001); and BAR 15.6 vs. 8.3 (p=0.001). No difference was found in terms of Donor Risk Index (DRI).

CONCLUSIONS

Retransplants exhibited lower survival rates at 30 days, as predicted by prognostic scores, but unrelated to the donor's condition.

Pragmatic strategies to address health disparities along the continuum of care in chronic liver disease

Racial, ethnic, and socioeconomic disparities exist in the prevalence and natural history of chronic liver disease, access to care, and clinical outcomes. Solutions to improve health equity range widely, from digital health tools to policy changes. The current review outlines the disparities along the chronic liver disease health care continuum from screening and diagnosis to the management of cirrhosis and considerations of pre-liver and post-liver transplantation. Using a health equity research and implementation science framework, we offer pragmatic strategies to address barriers to implementing high-quality equitable care for patients with chronic liver disease.

The potential of 18F-FDG PET/CT metabolic parameter-based nomogram in predicting the microvascular invasion of hepatocellular carcinoma before liver transplantation

PURPOSE

Microvascular invasion (MVI) is a critical factor in predicting the recurrence and prognosis of hepatocellular carcinoma (HCC) after liver transplantation (LT). However, there is a lack of reliable preoperative predictors for MVI. The purpose of this study is to evaluate the potential of an 18F-FDG PET/CT-based nomogram in predicting MVI before LT for HCC.

METHODS

83 HCC patients who obtained 18F-FDG PET/CT before LT were included in this retrospective research. To determine the parameters connected to MVI and to create a nomogram for MVI prediction, respectively, Logistic and Cox regression models were applied. Analyses of the calibration curve and receiver operating characteristic (ROC) curves were used to assess the model's capability to differentiate between clinical factors and metabolic data from PET/CT images.

RESULTS

Among the 83 patients analyzed, 41% were diagnosed with histologic MVI. Multivariate logistic regression analysis revealed that Child-Pugh stage, alpha-fetoprotein, number of tumors, CT Dmax, and Tumor-to-normal liver uptake ratio (TLR) were significant predictors of MVI. A nomogram was constructed using these predictors, which demonstrated strong calibration with a close agreement between predicted and actual MVI probabilities. The nomogram also showed excellent differentiation with an AUC of 0.965 (95% CI 0.925-1.000).

CONCLUSION

The nomogram based on 18F-FDG PET/CT metabolic characteristics is a reliable preoperative imaging biomarker for predicting MVI in HCC patients before undergoing LT. It has demonstrated excellent efficacy and high clinical applicability.

Early Graft Failure After Living-Donor Liver Transplant

BACKGROUND

Living-donor liver transplantation (LDLT) has been increasing in the USA. While data exist on longer-term patient and graft outcomes, a contemporary analysis of short-term outcomes is needed.

AIM

Evaluate short-term (30-day) graft failure rates and identify predictors associated with these outcomes.

METHODS

Adult (≥ 18) LDLT recipients from 01/2004 to 12/2021 were analyzed from the United States Scientific Registry of Transplant Recipients. Graft status at 30 days was assessed with graft failure defined as retransplantation or death. Comparison of continuous and categorical variables was performed and a multivariable logistic regression was used to identify risk factors of early graft failure.

RESULTS

During the study period, 4544 LDLTs were performed with a graft failure rate of 3.4% (155) at 30 days. Grafts from male donors (aOR: 0.63, CI 0.44-0.89), right lobe grafts (aOR: 0.40, CI 0.27-0.61), recipients aged > 60 years (aOR: 0.52, CI 0.32-0.86), and higher recipient albumin (aOR: 0.73, CI 0.57-0.93) were associated with superior early graft outcomes, whereas Asian recipient race (vs. White; aOR: 3.75, CI 1.98-7.10) and a history of recipient PVT (aOR: 2.7, CI 1.52-4.78) were associated with inferior outcomes. LDLTs performed during the most recent 2016-2021 period (compared to 2004-2009 and 2010-2015) resulted in significantly superior outcomes (aOR: 0.45, p < 0.001).

CONCLUSION

Our study demonstrates that while short-term adult LDLT graft failure is uncommon, there are opportunities for optimizing outcomes by prioritizing right lobe donation, improving candidate nutritional status, and careful pre-transplant risk assessment of candidates with known PVT. Notably, a period effect exists whereby increased LDLT experience in the most recent era correlated with improved outcomes.

UK guideline on the transition and management of childhood liver diseases in adulthood

INTRODUCTION

Improved outcomes of liver disease in childhood and young adulthood have resulted in an increasing number of young adults (YA) entering adult liver services. The adult hepatologist therefore requires a working knowledge in diseases that arise almost exclusively in children and their complications in adulthood.

AIMS

To provide adult hepatologists with succinct guidelines on aspects of transitional care in YA relevant to key disease aetiologies encountered in clinical practice.

METHODS

A systematic literature search was undertaken using the Pubmed, Medline, Web of Knowledge and Cochrane database from 1980 to 2023. MeSH search terms relating to liver diseases ('cholestatic liver diseases', 'biliary atresia', 'metabolic', 'paediatric liver diseases', 'autoimmune liver diseases'), transition to adult care ('transition services', 'young adult services') and adolescent care were used. The quality of evidence and the grading of recommendations were appraised using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system.

RESULTS

These guidelines deal with the transition of YA and address key aetiologies for the adult hepatologist under the following headings: (1) Models and provision of care; (2) screening and management of mental health disorders; (3) aetiologies; (4) timing and role of liver transplantation; and (5) sexual health and fertility.

CONCLUSIONS

These are the first nationally developed guidelines on the transition and management of childhood liver diseases in adulthood. They provide a framework upon which to base clinical care, which we envisage will lead to improved outcomes for YA with chronic liver disease.

Long-term outcomes of liver transplantation for biliary atresia and results of policy changes: over 20 years of follow-up experience

Objective

Biliary atresia (BA) patients develop chronic liver disease after the Kasai operation and are eventually indicated for liver transplantation (LT). The purposes of this study were to analyze long-term outcomes after LT and risk factors that affect complications to reduce graft failure.

Study design

Overall, 145 pediatric patients who underwent LT between June 1996 and June 2020 after a diagnosis of BA were included. We performed a retrospective analysis of medical records and evaluated patient and graft survival, cumulative incidence of complications, risk factors, and the results of policy changes.

Results

Patient and graft survival rates in over 20 years were 95.8% and 91.0%, respectively. Post-transplantation lymphoproliferative disease was frequently observed in the early period of immunosuppression within the first 1-2 years after LT. The incidence of cholangitis and rejection steadily increased over time. Weight-to-portal vein size was evaluated as a risk factor for cholangitis and bile duct strictures (OR = 12.82, p = 0.006 and OR = 16.54, p = 0.015, respectively). When evaluated using 2013 as a reference point, the split graft indication was expanded and the group that received LT after 2013 had a significantly lower survival over time compared with that of the group that received LT before 2013 (p = 0.006).

Conclusion

This study revealed time differences in prevalence of complications. The evaluation of weight-to-duct or vessel size is a more important factor in considering complications than the graft-to-recipient weight ratio. Survival outcomes may have been altered by a policy change that affects the donor type ratio in transplantation.

A humanized IL-2 mutein expands Tregs and prolongs transplant survival in preclinical models

Long-term organ transplant survival remains suboptimal, and life-long immunosuppression predisposes transplant recipients to an increased risk of infection, malignancy, and kidney toxicity. Promoting the regulatory arm of the immune system by expanding Tregs may allow immunosuppression minimization and improve long-term graft outcomes. While low-dose IL-2 treatment can expand Tregs, it has a short half-life and off-target expansion of NK and effector T cells, limiting its clinical applicability. Here, we designed a humanized mutein IL-2 with high Treg selectivity and a prolonged half-life due to the fusion of an Fc domain, which we termed mIL-2. We showed selective and sustainable Treg expansion by mIL-2 in 2 murine models of skin transplantation. This expansion led to donor-specific tolerance through robust increases in polyclonal and antigen-specific Tregs, along with enhanced Treg-suppressive function. We also showed that Treg expansion by mIL-2 could overcome the failure of calcineurin inhibitors or costimulation blockade to prolong the survival of major-mismatched skin grafts. Validating its translational potential, mIL-2 induced a selective and sustainable in vivo Treg expansion in cynomolgus monkeys and showed selectivity for human Tregs in vitro and in a humanized mouse model. This work demonstrated that mIL-2 can enhance immune regulation and promote long-term allograft survival, potentially minimizing immunosuppression.

Trends in Survival for Adult Organ Transplantation

Objective

Intent-to-treat analysis follows patients from listing to death, regardless of their transplant status, and aims to provide a more holistic scope of the progress made in adult solid-organ transplantation.

Background

Many studies have shown progress in waitlist and post-transplant survival for adult kidney, liver, heart, and lung transplants, but there is a need to provide a more comprehensive perspective of transplant outcomes for patients and their families.

Methods

Univariable and multivariable Cox regression analyses were used to analyze factors contributing to intent-to-treat survival in 813,862 adults listed for kidney, liver, heart, and lung transplants. The Kaplan-Meier method was used to examine changes in waitlist, post-transplant, and intent-to-treat survival. Transplantation rates were compared using χ2 tests.

Results

Intent-to-treat survival has steadily increased for liver, heart, and lung transplants. The percentage of patients transplanted within 1 year significantly increased for heart (57.4% from 52.9%) and lung (73.5% from 33.2%). However, the percentage of patients transplanted within 1 year significantly decreased from 35.8% to 21.2% for kidney transplant. Notably, intent-to-treat survival has decreased for kidneys despite increases in waitlist and post-transplant survival, likely because of the decreased transplant rate.

Conclusion

Intent-to-treat survival steadily improved for liver, heart, and lung transplant over the 30-year study period. Continued advancements in allocation policy, immunosuppression, and improved care of patients on the waitlist may contribute to further progress in outcomes of all organs, but the increasing discrepancy in supply and demand of donor kidneys is alarming and has impeded the progress of kidney intent-to-treat survival.

The Predictive Value of Graft Viability and Bioenergetics Testing Towards the Outcome in Liver Transplantation

Donor organ biomarkers with sufficient predictive value in liver transplantation (LT) are lacking. We herein evaluate liver viability and mitochondrial bioenergetics for their predictive capacity towards the outcome in LT. We enrolled 43 consecutive patients undergoing LT. Liver biopsy samples taken upon arrival after static cold storage were assessed by histology, real-time confocal imaging analysis (RTCA), and high-resolution respirometry (HRR) for mitochondrial respiration of tissue homogenates. Early allograft dysfunction (EAD) served as primary endpoint. HRR data were analysed with a focus on the efficacy of ATP production or P-L control efficiency, calculated as 1-L/P from the capacity of oxidative phosphorylation P and non-phosphorylating respiration L. Twenty-two recipients experienced EAD. Pre-transplant histology was not predictive of EAD. The mean RTCA score was significantly lower in the EAD cohort (-0.75 ± 2.27) compared to the IF cohort (0.70 ± 2.08; p = 0.01), indicating decreased cell viability. P-L control efficiency was predictive of EAD (0.76 ± 0.06 in IF vs. 0.70 ± 0.08 in EAD-livers; p = 0.02) and correlated with the RTCA score. Both RTCA and P-L control efficiency in biopsy samples taken during cold storage have predictive capacity towards the outcome in LT. Therefore, RTCA and HRR should be considered for risk stratification, viability assessment, and bioenergetic testing in liver transplantation.

Improved mortality prediction for pediatric acute liver failure using dynamic prediction strategy

OBJECTIVES

To develop and validate a prediction tool for pediatric acute liver failure (PALF) mortality risks that captures the rapid and heterogeneous clinical course for accurate and updated prediction.

METHODS

Data included 1144 participants with PALF enrolled during three phases of the PALF registry study over 15 years. Using joint modeling, we built a dynamic prediction tool for mortality by combining longitudinal trajectories of multiple laboratory and clinical variables. The predictive performance for 7-day and 21-day mortality was assessed using the area under curve (AUC) through cross-validation and split-by-time validation.

RESULTS

We constructed a prognostic joint model that combines the temporal trajectories of international normalized ratio, total bilirubin, hepatic encephalopathy, platelet count, and serum creatinine. Dynamic prediction using updated information improved predictive performance over static prediction using the information at enrollment (Day 0) only. In cross-validation, AUC increased from 0.784 to 0.887 when measurements obtained between Days 1 and 2 were incorporated. AUC remained similar when we used the earlier subset of the sample for training and the later subset for testing.

CONCLUSIONS

Serial measurements of five variables in the first few days of PALF capture the dynamic clinical course of the disease and improve risk prediction for mortality. Continuous disease monitoring and updating risk prognosis are beneficial for timely and judicious medical decisions.

Changes over time in self-efficacy and the allocation of responsibility for health management tasks in pediatric liver transplant recipients: Targets to improve the transition process

BACKGROUND

The process of transition to adult-based care encompasses a critical period in the life of an adolescent and young adult living with a chronic illness and one that comes with an increase in the risk of poor health outcomes. As yet, there is a dearth of empirical data to help optimize this process to ensure the best long-term outcome.

METHODS

This study used a principal components analysis to determine specific constructs measured by a revised version of the transition readiness survey used in our clinic. We investigated changes in these constructs over time. We further investigated the relationship between the change in these constructs over time spent in a focused transition program with adherence.

RESULTS

The primary component underlying our transition readiness survey for patients and parents represented self-efficacy. Time spent in the transition program was an independent predictor of change in self-efficacy (rho 0.299, p = .015); however, the magnitude of that change had no relationship to adherence. Change in parent-proxy self-efficacy was found to have a statistically significant relationship with tacrolimus standard deviation (rho -0.301, p = .026). There was disagreement identified between patient and parent responses on the survey. Neither change in patient nor parent reports of self-efficacy was found to have a relationship with post-transfer adherence.

CONCLUSIONS

This study reaches the novel conclusion that self-efficacy and parent-proxy self-efficacy are dynamic concepts that change over time spent in a focused transition program. The patient-parent disagreement and the relationship between parent-proxy self-efficacy and adherence stress the importance of involving parents/guardians in the transition process as well.

Dual alcohol and metabolic-related liver disease: Results from a population of liver transplant patients

BACKGROUND & AIMS

If alcohol-related liver disease (ALD) and nonalcoholic fatty liver disease (NAFLD) are now the two main indications for liver transplantation (LT), it has been recognized that both conditions can coexist in varying degrees and the concept of dual-aetiology fatty liver disease (DAFLD) has been proposed. This retrospective study aimed to evaluate, in a cohort of patients transplanted for ALD and NAFLD, the prevalence of DAFLD before LT and the impact on liver graft outcome.

METHODS

From 1990 to 2010, all patients who underwent LT for the so-called ALD or NAFLD in our centre were included. Before LT, DAFLD was defined as patients with a history of excessive alcohol consumption and obesity associated with either diabetes or hypertension. Before LT, patients were separated into three groups: DAFLD, ALD, and NAFLD. Fatty liver graft disease was classified according to the FLIP algorithm.

RESULTS

Out of 907, adult LT recipients were identified: 33 DAFLD patients, 333 ALD patients, and 24 NAFLD patients. After LT, ALD patients experienced significantly more alcohol relapse than DAFLD patients, who had twice more post-LT metabolic syndrome. Out of 926, post-LT biopsies, DAFLD patients had significantly more fatty liver graft disease due to metabolic syndrome features than ALD patients.

CONCLUSION

Our results support that DAFLD recently emerged as an indication of LT. In the future, this particular population needs to be identified as a specific entity since post-LT outcome on the graft is different from ALD and more similar to NAFLD patients.

Impact of early immunosuppression on pediatric liver transplant outcomes within 1 year

OBJECTIVES

The Starzl Network for Excellence in Pediatric Transplantation identified optimizing immunosuppression (IS) as a priority practice improvement area for patients, families, and providers. We aimed to evaluate associations between clinical characteristics, early IS, and outcomes.

METHODS

We analyzed pediatric liver transplant (LT) data from 2013 to 2018 in the United Network for Organ Sharing (UNOS) and the Society of Pediatric Liver Transplantation (SPLIT) registries.

RESULTS

We included 2542 LT recipients in UNOS and 1590 in SPLIT. IS choice varied between centers with steroid induction and mycophenolate mofetil (MMF) use each ranging from 0% to 100% across centers. Clinical characteristics associated with early IS choice were inconsistent between the two data sets. T-cell depleting antibody use was associated with improved 1-year graft (hazard ratio [HR] 0.50, 95% confidence interval [CI] 0.34-0.76) and patient (HR 0.40, 95% CI 0.20-0.79) survival in UNOS but decreased 1-year patient survival (HR 4.12, 95% CI 1.31-12.93) and increased acute rejection (HR 1.58, 95% CI 1.07-2.34) in SPLIT. Non-T-cell depleting antibody use was not associated with differential risk of survival nor rejection. MMF use was associated with improved 1-year graft survival (HR 0.73, 95% CI 0.54-0.99) in UNOS only.

CONCLUSIONS

Variation exists in center choice of early IS regimen. UNOS and SPLIT data provide conflicting associations between IS and outcomes in multivariable analysis. These results highlight the need for future multicenter collaborative work to identify evidence-based IS best practices.

The triglyceride-glucose index: a novel predictor of stroke and all-cause mortality in liver transplantation recipients

BACKGROUND

The triglyceride-glucose (TyG) index, identified as a reliable indicator of insulin resistance (IR), was reported to be associated with stroke recurrence and morbidity in the general population and critically ill patients. However, the relationship in liver transplantation (LT) recipients remains unknown. This study aimed to investigate the correlation between the TyG index and post-LT stroke along with all-cause mortality and further assess the influence of IR on the LT recipients' prognosis.

METHODS

The retrospective cohort study enrolled 959 patients who underwent LT at a university-based medical centre between January 2015 and January 2021. The participants were divided into three groups according to their TyG index tertiles. The primary outcome was post-LT stroke. Multivariate logistic regression, COX proportional hazards regression, and restricted cubic spline RCS were used to examine the association between the TyG index and outcomes in LT recipients.

RESULTS

With a median TyG index of 8.23 (7.78-8.72), 780 (87.18% males) patients were eventually included. The incidence of post-LT stroke was 5.38%, and the in-hospital, 1-year, and 3-year mortality rates were 5.54%, 13.21%, and 15.77%, respectively. Multivariate regression analysis showed an independent association between the TyG index and an increased risk of post-LT stroke [adjusted odds ratio (aOR), 3.398 (95% confidence interval [CI]: 1.371-8.426) P = 0. 008], in-hospital mortality [adjusted hazard ratio (aHR), 2.326 (95% CI: 1.089-4.931) P = 0.025], 1-year mortality [aHR, 1.668 (95% CI: 1.024-2.717) P = 0.039], and 3-year mortality [aHR, 1.837 (95% CI: 1.445-2.950) P = 0.012]. Additional RCS analysis also suggested a linear increase in the risk of postoperative stroke with elevated TyG index (P for nonlinearity = 0.480).

CONCLUSIONS

The TyG index may be a valuable and reliable indicator for assessing stroke risk and all-cause mortality in patients undergoing LT, suggesting its potential relevance in improving risk stratification during the peri-LT period.

Causes of death and associated factors with death after liver transplantation: a nationwide database study

BACKGROUND/AIMS

This study investigated overall, 1-year, and 5-year mortality rate, the causes of death, and associated factors with death in liver transplantation recipients.

METHODS

A total of 11,590 liver transplant recipients identified from National Health Insurance Service database between 2006 and 2017 were included. Factors associated with all-cause of death were analyzed by Cox proportional regression models. Cumulative mortality rate according to the underlying indication was estimated by Kaplan-Meier method.

RESULTS

The 12-year survival rate for all liver transplant recipients was 68%. In the overall, 1-year, and 5-year mortality of liver transplant recipients, hepatic death was the highest contributing risk, accounting for >65% of the causes of death. Deaths from cirrhosis and liver failure accounted for a high proportion of deaths within 1 year after transplantation, and deaths from malignant tumors such as hepatocellular carcinoma were high among late-stage deaths.

DISCUSSION

Although the most common cause of death from liver transplantation is due to primary disease, there was a difference in the pattern of major causes of death according to the period from transplantation to death. If appropriate medical intervention is performed at each period after transplantation, the survival rate can be improved.

Improved Early Post-Transplant Outcomes and Organ Use in Kidney Transplant Using Normothermic Regional Perfusion for Donation after Circulatory Death: National Experience in the US

BACKGROUND

Normothermic regional perfusion (NRP) is a technique that is intended to enhance organ transplant outcomes from donation circulatory death (DCD) donors.

STUDY DESIGN

A retrospective analysis of data from the Scientific Registry of Transplant Recipients was performed. DCD donors were screened for inclusion based on date of donation 2020 or later, and whether the heart was also recovered for transplantation. We grouped donors as either donation after brain death or DCD. DCD donors were further divided into groups including those in which the heart was not recovered for transplant (Non-Heart DCD) and those in which it was, based on recovery technique (thoracoabdominal-NRP [TA-NRP] Heart DCD and Super Rapid Recovery Heart DCD).

RESULTS

A total of 219 kidney transplant recipients receiving organs from TA-NRP Heart DCD donors were compared to 436 SRR Super Rapid Recovery DCD, 10,630 Super Rapid Recovery non-heart DCD, and 27,820 donations after brain death recipients. Kidney transplant recipients of TA-NRP DCD allografts experienced shorter length of stay, lower rates of delayed graft function, and lower serum creatinine at the time of discharge when compared with recipients of other DCD allografts.

CONCLUSIONS

Our analysis demonstrates superior early kidney allograft function when TA-NRP is used for DCD organ recovery.

Optimal Liver Transplantation Criteria for Hepatocellular Carcinoma

Liver transplantation continues to be the optimal treatment for hepatocellular carcinoma (HCC). Given the limited organ supply, patient selection for liver transplant must carefully balance tumor progression with risk of recurrence posttransplant. There are several pretransplant selection criteria that incorporate biomarkers as well as imaging modality to risk-stratify patients as we continue to look for the optimal transplant cutoff for patients with HCC, which should be transplant-center specific, and account for organ availability and dynamic response to locoregional therapy.

Incidence and Risk Factors of Acute Kidney Injury in Pediatric Liver Transplant Patients: A Retrospective Study

Background

Acute kidney injury (AKI) significantly contributes to the mortality and morbidity rates among pediatric liver transplant (LT) recipients.

Objective

Our study aimed to assess the potential factors contributing to AKI in pediatric LT patients and to analyze the impact of AKI on postoperative mortality and hospitalization duration.

Materials and methods

About 235 pediatric LT patients under the age of 18 between the years 2015 and 2021 were evaluated retrospectively. The relationship between preoperative and intraoperative variables of the patients and AKI developed when the early postoperatıve period was assessed.

Results

A correlation was found between the patients' preoperative age, albumin levels, and AKI. AKI was found to be associated with the duration of surgery and intraoperative blood transfusion.

Conclusion

Our findings revealed that the severity of AKI in pediatric LT patients is linked to extended surgical durations and increased blood transfusions resulting from hemodynamically compromised blood loss. Furthermore, independent risk factors for AKI were identified as prolonged warm ischemia and the overall duration of the operation.

How to cite this article

Demiroz D, Colak YZ, Ozdes OO, Ucar M, Ali Erdogan M, Toprak HI, et al. Incidence and Risk Factors of Acute Kidney İnjury in Pediatric Liver Transplant Patients: A Retrospective Study. Indian J Crit Care Med 2024;28(1):75-79.

Progress in preservation of intestinal grafts by oxygenated hypothermic machine perfusion

Intestine transplantation (IT) is a critical treatment strategy for irreversible intestinal failure. Among all abdominal solid organ transplants, the intestine was the most vulnerable to ischemia and reperfusion injury (IRI). The static cold storage (SCS) technique is currently the most commonly used graft preservation method, but its hypoxia condition causes metabolic disorders, resulting in the occurrence of IRI, limiting its application in marginal organs. It is especially important to improve preservation techniques in order to minimize damage to marginal donor organs, which draws more attention to machine perfusion (MP). There has been much debate about whether it is necessary to increase oxygen in these conditions to support low levels of metabolism since the use of machine perfusion to preserve organs. There is evidence that oxygenation helps to restore intracellular ATP levels in the intestine after thermal or cold ischemia damage. The goal of this review is to provide an overview of the role of oxygen in maintaining environmental stability in the gut under hypoxic conditions, as well as to investigate the possibilities and mechanisms of oxygen delivery during preservation in intestine transplantation studies and clinical models.

Outcomes in elderly patients undergoing hepatic resection compared to liver transplant for hepatocellular carcinoma

BACKGROUND

Hepatic resection (HR) is an excellent option for patients with hepatocellular carcinoma (HCC). For patients meeting the Milan criteria, a liver transplant (LT) is also a viable option for patients with HCC, especially those with end-stage liver disease. With increasing rates of LTs amongst the elderly, we sought to determine long-term outcomes in patients who underwent HR compared to LTs in this patient population.

METHODS

We queried the national cancer database for elderly patients (≥70 years) diagnosed with HCC between 2004 and 2020. The primary outcome was overall survival (OS) computed using the Kaplan-Meier method and Cox proportional hazard regression. One-to-one propensity score matching was conducted on the basis of clinicodemographic features to account for baseline differences between patients undergoing each procedure.

RESULTS

Of the 5090 patients included, 4674 (91.8%) and 416 (8.2%) patients underwent HR and LT, respectively. Compared with HR patients, patients receiving LT had better OS (p < 0.001) and greater median survival time (65.6 months HR vs. 97.9 months LT, p < 0.001). On multivariable analysis, a LT was independently associated with improved survival (adjusted hazard ratio: 0.61, 95% confidence interval: 0.50-0.76, p < 0.001).

CONCLUSIONS

LT is associated with improved survival for well-selected elderly patients with HCC. Age alone should not be used as the sole parameter for the candidacy of LT in elderly patients.

Transplant Candidate Outcomes After Declining a DCD Liver in the United States

BACKGROUND

In the context of the organ shortage, donation after circulatory death (DCD) provides an opportunity to expand the donor pool. Although deceased-donor liver transplantation from DCD donors has expanded, DCD livers continue to be discarded at elevated rates; the use of DCD livers from older donors, or donors with comorbidities, is controversial.

METHODS

Using US registry data from 2009 to 2020, we identified 1564 candidates on whose behalf a DCD liver offer was accepted ("acceptors") and 16 981 candidates on whose behalf the same DCD offers were declined ("decliners"). We characterized outcomes of decliners using a competing risk framework and estimated the survival benefit (adjusted hazard ratio [95% confidence interval]) of accepting DCD livers using Cox regression.

RESULTS

Within 10 y of DCD offer decline, 50.9% of candidates died or were removed from the waitlist before transplantation with any type of allograft. DCD acceptors had lower mortality compared with decliners at 10 y postoffer (35.4% versus 48.9%, P < 0.001). After adjustment for candidate covariates, DCD offer acceptance was associated with a 46% reduction in mortality (0.54 [0.49-0.61]). Acceptors of older (age ≥50), obese (body mass index ≥30), hypertensive, nonlocal, diabetic, and increased risk DCD livers had 44% (0.56 [0.42-0.73]), 40% (0.60 [0.49-0.74]), 48% (0.52 [0.41-0.66]), 46% (0.54 [0.45-0.65]), 32% (0.68 [0.43-1.05]), and 45% (0.55 [0.42-0.72]) lower mortality risk compared with DCD decliners, respectively.

CONCLUSIONS

DCD offer acceptance is associated with considerable long-term survival benefits for liver transplant candidates, even with older DCD donors or donors with comorbidities. Increased recovery and utilization of DCD livers should be encouraged.

Cumulative exposure to tacrolimus during early period after liver transplantation does not affect the recurrence of hepatocellular carcinoma

The clinical effects of tacrolimus (TAC) exposure on hepatocellular carcinoma (HCC) recurrence after liver transplantation (LT) remain unclear. In this retrospective single centric study, 512 patients who underwent LT for HCC were divided into four groups according to cumulative exposure to tacrolimus (CET) during 3 months after LT: conventional (n = 218), aggressive minimization (n = 32), minimization (n = 161), and high exposure (n = 101). Impact of CET on HCC recurrence and death were analyzed. Compared with the conventional group, the other three CET groups showed a similar risk of HCC recurrence. The aggressive minimization group showed a higher risk [hazard ratio (HR) 5.64, P < 0.001] and the high exposure group showed a marginal risk (HR 1.67, P = 0.081) of overall death compared to the conventional group. CET during 3 months was not associated with HCC recurrence in the matched cohort and various subgroups. TAC minimization is not effective to prevent HCC recurrence but could result in higher mortality in LT recipients.

Safety and outcomes of hip and knee replacement surgery in liver transplant recipients

BACKGROUND

Liver transplant (LT) is becoming increasingly common with improved life expectancy. Joint replacement is usually a safe procedure; however, its safety in LT recipients remains understudied.

AIM

To evaluate the mortality, outcome, and 90-d readmission rate in LT patients undergoing hip and knee replacement surgery.

METHODS

Patients with history of LT who underwent hip and knee replacement surgery between 2016 and 2019 were identified using the National Readmission Database.

RESULTS

A total of 5046119 hip and knee replacement surgeries were identified. 3219 patients had prior LT. Mean age of patients with no history of LT was 67.51 [95% confidence interval (CI): 67.44-67.58], while it was 64.05 (95%CI: 63.55-64.54) in patients with LT. Patients with history of LT were more likely to have prolonged length of hospital stay (17.1% vs 8.4%, P < 0.001). The mortality rate for patients with no history of LT was 0.22%, while it was 0.24% for patients with LT (P = 0.792). Patients with history of LT were more likely to have re-admissions within 90 d of initial hospitalization: 11.4% as compared to 6.2% in patients without history of LT (P < 0.001). The mortality rate between both groups during readmission was not statistically different (1.9% vs 2%, P = 0.871) respectively.

CONCLUSION

Hip and knee replacements in patients with history of LT are not associated with increased mortality; increased re-admissions were more frequent in this cohort of patients. Chronic kidney disease and congestive heart failure appear to predict higher risk of readmission.

Factors associated with mechanical ventilation longer than 24 h after liver transplantation in patients at risk for bleeding

BACKGROUND

This risk analysis aimed to explore all modifiable factors associated with prolonged mechanical ventilation (lasting > 24 h) after liver transplantation, based on prospectively collected data from a clinical trial.

METHODS

We evaluated 306 candidates. Ninety-three patients were excluded for low risk for transfusion (preoperative haemoglobin > 130 g.l-1), and 31 patients were excluded for anticoagulation therapy, bleeding disorders, familial polyneuropathy, or emergency status. Risk factors were initially identified with a log-binomial regression model. Relative risk was then calculated and adjusted for age, sex, and disease severity (Model for End-Stage Liver Disease [MELD] score).

RESULTS

Early tracheal extubation was performed in 149 patients (84.7%), and 27 patients (15.3%) required prolonged mechanical ventilation. Reoperations were required for 6.04% of the early extubated patients and 44% of patients who underwent prolonged ventilation (p = 0.001). A MELD score > 23 was the main risk factor for prolonged ventilation. Once modifiable risk factors were adjusted for MELD score, sex, and age, three factors were significantly associated with prolonged ventilation: tranexamic acid (p = 0.007) and red blood cell (p = 0.001) infusion and the occurrence of postreperfusion syndrome (p = 0.004). The median (IQR) ICU stay was 3 (2-4) days in the early extubation group vs. 5 (3-10) days in the prolonged ventilation group (p = 0.001). The median hospital stay was also significantly shorter after early extubation, at 14 (10-24) days, vs. 25 (14-55) days in the prolonged ventilation group (p = 0.001). Eight patients in the early-extubation group (5.52%) were readmitted to the ICU, nearly all for reoperations, with no between-group differences in ICU readmissions (prolonged ventilation group, 3.7%).

CONCLUSION

We conclude that bleeding and postreperfusion syndrome are the main modifiable factors associated with prolonged mechanical ventilation and length of ICU stay, suggesting that trials should explore vasopressor support strategies and other interventions prior to graft reperfusion that might prevent potential fibrinolysis.

TRIAL REGISTRATION

European Clinical Trials Database (EudraCT 2018-002510-13,) and on ClinicalTrials.gov (NCT01539057).

Immune Features of Disparate Liver Transplant Outcomes in Female Hispanics With Nonalcoholic Steatohepatitis

Background

Nonalcoholic steatohepatitis (NASH) is a severe immune-mediated stage of nonalcoholic fatty liver disease that is rapidly becoming the most common etiology requiring liver transplantation (LT), with Hispanics bearing a disproportionate burden. This study aimed to uncover the underlying immune mechanisms of the disparities experienced by Hispanic patients undergoing LT for NASH.

Methods

We enrolled 164 LT recipients in our institutional review board-approved study, 33 of whom presented with NASH as the primary etiology of LT (20%), with 16 self-reported as Hispanic (48%). We investigated the histopathology of prereperfusion and postreperfusion biopsies, clinical liver function tests, longitudinal soluble cytokines via 38-plex Luminex, and immune cell phenotypes generated by prereperfusion and postreperfusion blood using 14-color flow cytometry and enzyme-linked immunosorbent assay.

Results

Hispanic LT recipients transplanted for NASH were disproportionately female (81%) and disproportionately suffered poor outcomes in the first year posttransplant, including rejection (26%) and death (38%). Clinically, we observed increased pro-inflammatory and apoptotic histopathological features in biopsies, increased AST/international normalized ratio early posttransplantation, and a higher incidence of presensitization to mismatched HLA antigens expressed by the donor allograft. Experimental investigations revealed that blood from female Hispanic NASH patients showed significantly increased levels of leukocyte-attracting chemokines, innate-to-adaptive switching cytokines and growth factors, HMGB1 release, and TLR4/TLR8/TLR9/NOD1 activation, and produced a pro-inflammatory, pro-apoptotic macrophage phenotype with reduced CD14/CD68/CD66a/TIM-3 and increased CD16/CD11b/HLA-DR/CD80.

Conclusions

A personalized approach to reducing immunological risk factors is urgently needed for this endotype in Hispanics with NASH requiring LT, particularly in females.

Collaborative leadership in transplantation: Blending clinical, business, and regulatory roles

Transplantation is a high-risk, high-cost treatment for end-stage diseases and is the most strictly regulated area of healthcare in the United States. Thus, achieving success for patients and the program requires skillful and collaborative leadership. Various factors, such as outcomes, volume, and financial health, may measure the success of a transplant program. Strong collaboration between clinical and administrative leaders is key to achieving and maintaining success in those three categories. Clinical leaders of adult programs, such as medical and surgical directors, bear the primary responsibility for a program's volume, outcomes, and patient safety, while administrative directors are focused on business intelligence and regulatory compliance. This paper aims to provide readers with insights into the critical role of collaborative leadership in running a successful program, with a focus on clinical, business, and regulatory perspectives.

Utilization of Segmental Grafts Is Associated With Higher Transplant Rates in Pediatric Patients

INTRODUCTION

In July 2017, a policy to increase the use of segmental grafts (SGs) was implemented at our institution. The aim was to compare changes in waitlist activity after implementation of this policy.

METHODS

A single-center, retrospective study. Pediatric patients on the liver waiting list between January 2015 and December 2019 were screened. Patients were classified as receiving a liver transplant (LT) before (Period 1) or after (Period 2) policy changes. Primary end points were transplant rates and time to transplant.

RESULTS

Sixty five first LT performed on 65 patients were included. Twenty nine LT were performed during Period 1 and 36 during Period 2. More than half (55%) of LT in Period 2 were SG, compared to 10.3% in Period 1 (P < 0.001). Forty nine and 56 pediatric candidates on the waiting list accounted for 38.78 and 24.48 person-years during Period 1 and Period 2, respectively. Transplant rates per 100 person-years on the waiting list increased from 85.09 during Period 1 to 187.87 in Period 2 (Rate ratio: 2.20; P < 0.001). Median time to receive a LT decreased from 229 d in Period 1 to 75 d during Period 2 (P = 0.013). One-year patient survival rates were 96.6% in Period 1 and 95.7% in Period 2. One-year graft survival rates were 89.7% and 88% in Period 1 and Period 2, respectively.

CONCLUSIONS

A policy to increase the use of SG was associated with significantly higher transplant rates and lower waiting times. Implementation of this policy can be done successfully with no observed negative impact on patient and graft survival.

Effectiveness of tacrolimus in a case of immune checkpoint inhibitor-induced hepatotoxicity that was refractory to steroids and mycophenolate mofetil

Immune checkpoint inhibitors (ICIs) sometimes induce immune-mediated hepatotoxicity (IMH), and corticosteroids and mycophenolate mofetil (MMF) are recommended for the treatment of IMH. However, there is no consensus on the treatment of IMH refractory to these drugs. Here, we report a case of refractory IMH that was successfully treated with tacrolimus. A 69-year-old man presented with liver injury after receiving durvalumab, an ICI, for lung cancer. He was diagnosed with IMH and received corticosteroids including methylprednisolone pulses and MMF, but his liver damage did not improve. Liver histology showed infiltration of inflammatory cells, mainly CD8 + T cells, in the portal area. Tacrolimus was added to corticosteroid and MMF to suppress mainly T cells. After the tacrolimus administration, the liver damage promptly improved. Since IMH is thought to be caused by activated CD8 + T-cell infiltration, T-cell suppression may be an effective treatment. This case suggests that tacrolimus may be an effective option for IMH refractory to corticosteroids or MMF if CD8 + T-cell infiltration is confirmed in the liver tissue.

International Liver Transplantation Society Global Census: First Look at Pediatric Liver Transplantation Activity Around the World

BACKGROUND

Over 16 000 children under the age of 15 died worldwide in 2017 because of liver disease. Pediatric liver transplantation (PLT) is currently the standard of care for these patients. The aim of this study is to describe global PLT activity and identify variations between regions.

METHODS

A survey was conducted from May 2018 to August 2019 to determine the current state of PLT. Transplant centers were categorized into quintile categories according to the year they performed their first PLT. Countries were classified according to gross national income per capita.

RESULTS

One hundred eight programs from 38 countries were included (68% response rate). 10 619 PLTs were performed within the last 5 y. High-income countries performed 4992 (46.4%) PLT, followed by upper-middle- (4704 [44·3%]) and lower-middle (993 [9·4%])-income countries. The most frequently used type of grafts worldwide are living donor grafts. A higher proportion of lower-middle-income countries (68·7%) performed ≥25 living donor liver transplants over the last 5 y compared to high-income countries (36%; P = 0.019). A greater proportion of programs from high-income countries have performed ≥25 whole liver transplants (52.4% versus 6.2%; P = 0.001) and ≥25 split/reduced liver transplants (53.2% versus 6.2%; P < 0.001) compared to lower-middle-income countries.

CONCLUSIONS

This study represents, to our knowledge, the most geographically comprehensive report on PLT activity and a first step toward global collaboration and data sharing for the greater good of children with liver disease; it is imperative that these centers share the lead in PLT.

Hepatitis C virus-positive donors in HCV-negative recipients in liver transplantation: Is it possible in Mexico?

Hepatitis C virus (HCV) infection is a worldwide public health problem associated with significant morbidity and mortality. In the context of liver transplantation, the demand for organs continues to exceed the supply, prompting the consideration of using organs from HCV-positive donors in HCV-negative recipients. The introduction of direct-acting antivirals (DAAs), which have demonstrated great efficacy in eradicating the virus, has made transplantation of organs from donors with HCV infection possible. The present article provides a brief review of the current evidence on the use of organs from HCV-infected patients.

Perspectives on Scaffold Designs with Roles in Liver Cell Asymmetry and Medical and Industrial Applications by Using a New Type of Specialized 3D Bioprinter

Cellular asymmetry is an important element of efficiency in the compartmentalization of intracellular chemical reactions that ensure efficient tissue function. Improving the current 3D printing methods by using cellular asymmetry is essential in producing complex tissues and organs such as the liver. The use of cell spots containing at least two cells and basement membrane-like bio support materials allows cells to be tethered at two points on the basement membrane and with another cell in order to maintain cell asymmetry. Our model is a new type of 3D bioprinter that uses oriented multicellular complexes with cellular asymmetry. This novel approach is necessary to replace the sequential and slow processes of organogenesis with rapid methods of growth and 3D organ printing. The use of the extracellular matrix in the process of bioprinting with cells allows one to preserve the cellular asymmetry in the 3D printing process and thus preserve the compartmentalization of biological processes and metabolic efficiency.

Patient randomised controlled trial of technology enabled strategies to promote treatment adherence in liver transplantation: rationale and design of the TEST trial

BACKGROUND AND AIMS

Liver transplantation is a life-saving procedure for end-stage liver disease. However, post-transplant medication regimens are complex and non-adherence is common. Post-transplant medication non-adherence is associated with graft rejection, which can have long-term adverse consequences. Transplant centres are equipped with clinical staff that monitor patients post-transplant; however, digital health tools and proactive immunosuppression adherence monitoring has potential to improve outcomes.

METHODS AND ANALYSIS

This is a patient-randomised prospective clinical trial at three transplant centres in the Northeast, Midwest and South to investigate the effects of a remotely administered adherence programme compared with usual care. The programme monitors potential non-adherence largely levering text message prompts and phenotypes the nature of the non-adhere as cognitive, psychological, medical, social or economic. Additional reminders for medications, clinical appointments and routine self-management support are incorporated to promote adherence to the entire medical regimen. The primary study outcome is medication adherence via 24-hour recall; secondary outcomes include additional medication adherence (ASK-12 self-reported scale, regimen knowledge scales, tacrolimus values), quality of life, functional health status and clinical outcomes (eg, days hospitalised). Study implementation, acceptability, feasibility, costs and potential cost-effectiveness will also be evaluated.

ETHICS AND DISSEMINATION

The University of Pennsylvania Review Board has approved the study as the single IRB of record (protocol # 849575, V.1.4). Results will be published in peer-reviewed journals and summaries will be provided to study funders.

TRIAL REGISTRATION NUMBER

NCT05260268.

Machine perfusion in liver transplantation

BACKGROUND

Liver transplantation is the only chance of cure for people with end-stage liver disease and some people with advanced liver cancers or acute liver failure. The increasing prevalence of these conditions drives demand and necessitates the increasing use of donated livers which have traditionally been considered suboptimal. Several novel machine perfusion preservation technologies have been developed, which attempt to ameliorate some of the deleterious effects of ischaemia reperfusion injury. Machine perfusion technology aims to improve organ quality, thereby improving outcomes in recipients of suboptimal livers when compared to traditional static cold storage (SCS; ice box).

OBJECTIVES

To evaluate the effects of different methods of machine perfusion (including hypothermic oxygenated machine perfusion (HOPE), normothermic machine perfusion (NMP), controlled oxygenated rewarming, and normothermic regional perfusion) versus each other or versus static cold storage (SCS) in people undergoing liver transplantation.

SEARCH METHODS

We used standard, extensive Cochrane search methods. The latest search date was 10 January 2023.

SELECTION CRITERIA

We included randomised clinical trials which compared different methods of machine perfusion, either with each other or with SCS. Studies comparing HOPE via both hepatic artery and portal vein, or via portal vein only, were grouped. The protocol detailed that we also planned to include quasi-randomised studies to assess treatment harms.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Our primary outcomes were 1. overall participant survival, 2. quality of life, and 3. serious adverse events. Secondary outcomes were 4. graft survival, 5. ischaemic biliary complications, 6. primary non-function of the graft, 7. early allograft function, 8. non-serious adverse events, 9. transplant utilisation, and 10. transaminase release during the first week post-transplant. We assessed bias using Cochrane's RoB 2 tool and used GRADE to assess certainty of evidence.

MAIN RESULTS

We included seven randomised trials (1024 transplant recipients from 1301 randomised/included livers). All trials were parallel two-group trials; four compared HOPE versus SCS, and three compared NMP versus SCS. No trials used normothermic regional perfusion. When compared with SCS, it was uncertain whether overall participant survival was improved with either HOPE (hazard ratio (HR) 0.91, 95% confidence interval (CI) 0.42 to 1.98; P = 0.81, I2 = 0%; 4 trials, 482 recipients; low-certainty evidence due to imprecision because of low number of events) or NMP (HR 1.08, 95% CI 0.31 to 3.80; P = 0.90; 1 trial, 222 recipients; very low-certainty evidence due to imprecision and risk of bias). No trials reported quality of life. When compared with SCS alone, HOPE was associated with improvement in the following clinically relevant outcomes: graft survival (HR 0.45, 95% CI 0.23 to 0.87; P = 0.02, I2 = 0%; 4 trials, 482 recipients; high-certainty evidence), serious adverse events in extended criteria DBD liver transplants (OR 0.45, 95% CI 0.22 to 0.91; P = 0.03, I2 = 0%; 2 trials, 156 participants; moderate-certainty evidence) and clinically significant ischaemic cholangiopathy in recipients of DCD livers (OR 0.31, 95% CI 0.11 to 0.92; P = 0.03; 1 trial, 156 recipients; high-certainty evidence). In contrast, NMP was not associated with improvement in any of these clinically relevant outcomes. NMP was associated with improved utilisation compared with SCS (one trial found a 50% lower rate of organ discard; P = 0.008), but the reasons underlying this effect are unknown. We identified 11 ongoing studies investigating machine perfusion technologies.

AUTHORS' CONCLUSIONS

In situations where the decision has been made to transplant a liver donated after circulatory death or donated following brain death, end-ischaemic HOPE will provide superior clinically relevant outcomes compared with SCS alone. Specifically, graft survival is improved (high-certainty evidence), serious adverse events are reduced (moderate-certainty evidence), and in donors after circulatory death, clinically relevant ischaemic biliary complications are reduced (high-certainty evidence). There is no good evidence that NMP has the same benefits over SCS in terms of these clinically relevant outcomes. NMP does appear to improve utilisation of grafts that would otherwise be discarded with SCS; however, the reasons for this, and whether this effect is specific to NMP, is not clear. Further studies into NMP viability criteria and utilisation, as well as head-to-head trials with other perfusion technologies are needed. In the setting of donation following circulatory death transplantation, further trials are needed to assess the effect of these ex situ machine perfusion methods against, or in combination with, normothermic regional perfusion.

Clinical trials reimagined

Clinical trials have been a central driver of change and have provided the evidence base necessary to advance new therapies for liver diseases. This review provides a perspective on the status of trials in hepatology and a vantage point into the emerging capabilities and external forces that will shape the conduct of clinical trials in the future. The adaptations to clinical trial operations in response to the disruptions by the COVID-19 pandemic and opportunities for innovation in hepatology trials are emphasized. Future trials in hepatology will be driven by unmet therapeutic needs and fueled by technological advances incorporating digital capabilities with expanded participant-derived data collection, computing, and analytics. Their design will embrace innovative trial designs adapted to these advances and that emphasize broader and more inclusive participant engagement. Their conduct will be further shaped by evolving regulatory needs and the emergence of new stakeholders in the clinical trials ecosystem. The evolution of clinical trials will offer unique opportunities to advance new therapeutics that will ultimately improve the lives of patients with liver diseases.

Split or whole liver transplantation? Utilization and posttransplant survival

BACKGROUND

Split liver transplantation (SLT), where a single donor liver is divided for transplantation to 2 recipients, has the potential to increase the availability of size-matched livers for pediatric candidates and expand the supply of donor organs available for adult candidates. Although SLT is a well-established technique, the number of SLTs has remained flat during the past 2 decades, partly due to concerns about the posttransplant survival of SLT recipients compared with whole liver transplantation (WLT) recipients. Prior work on SLT versus WLT survival analysis had limitations because, for pediatric recipients, it did not consider the correlations between donor age/weight and the allograft type, and for adult recipients, it may have included records where the donor livers did not meet the split liver criteria (splittable).

METHODS

Using the Organ Procurement and Transplantation Network's database (2003-2019), this study analyzes and compares (i) key characteristics of donors and recipients, (ii) donor-recipient match dynamics (organ offers and accept/decline decisions), and (iii) recipient posttransplant survival, for SLT and WLT.

RESULTS AND CONCLUSIONS

The results in this study show that the posttransplant survival of SLT and WLT recipients is similar (controlling for other confounding factors that may impact posttransplant survival), highlighting the importance of SLT for increasing the liver supply and potential benefits for both pediatric and adult candidates.

Successful liver transplantation from deceased donors with active COVID-19 infections with undetectable SARS-CoV-2 in donor liver and aorta

BACKGROUND

The COVID-19 pandemic, caused by the SARS-CoV-2 virus, has had unprecedented effects on society and modern healthcare. In liver transplantation, uncertainty regarding the safety of performing transplants during the early stage of the pandemic resulted in increased waitlist mortality. Additionally, concerns about disease transmission led to avoidance of deceased donors with COVID-19 infections. Several successful case reports describing incidental transplant of organs from donors with COVID-19 infections or intentional transplant of such donors into recipients with current or prior COVID-19 infections prompted the transplant community to re-evaluate that position. While excellent short-term results have been published, little is known about use of donors with active infections and the extent of COVID-19 organ involvement, which may affect long term outcomes.

METHODS

We report the successful transplantation of three livers from deceased donors with active COVID-19 infections. Donor liver and aortic tissues were evaluated by sensitive molecular testing for SARS-CoV-2 RNA via in situ hybridization and real-time quantitative reverse transcription PCR.

RESULTS

Postoperatively, all patients had excellent allograft function, without clinical or molecular evidence of SARS-CoV-2 transmission in donor tissues.

CONCLUSION

This evidence supports the use of liver donors with active COVID-19 infections.

The evolution of the liver transplant candidate

The first successful human liver transplant (LT) was done over 60 years ago; since the early pioneering days, this procedure has become a routine treatment with excellent outcomes for the great majority of recipients. Over the last six decades, indications have evolved. Use of LT for hepatic malignancy is becoming less common as factors that define a successful outcome are being increasingly defined, and alternative therapeutic options become available. Both Hepatitis B and C virus associated liver disease are becoming less common indications as medical treatments become more effective in preventing end-stage disease. Currently, the most common indications are alcohol-related liver disease and metabolic associated liver disease. The developing (and controversial) indications include acute on chronic liver failure, alcoholic hepatitis and some rarer malignancies such as non-resectable colorectal cancer liver metastases, neuroendocrine tumours and cholangiocarcinoma. Candidates are becoming older and with greater comorbidities, A relative shortage of donor organs remains the greatest cause for reducing access to LT; therefore, various countries have developed transparent approaches to allocation of this life saving and life enhancing resource. Reliance on prognostic models has gone some way to improve transparency and increase equity of access but these approaches have their limitations.

Adjuvant conditioning induces an immunosuppressive milieu that delays alloislet rejection through the expansion of myeloid-derived suppressor cells

Advances in immunosuppression have been relatively stagnant over the past 2 decades, and transplant recipients continue to experience long-term morbidity associated with immunosuppression regimens. Strategies to reduce or eliminate the dosage of immunosuppression medications are needed. We discovered a novel administration strategy using the classic adjuvant alum to condition murine islet transplant recipients, known as adjuvant conditioning (AC), to expand both polymorphonuclear and monocytic myeloid-derived suppressive cells (MDSCs) in vivo. These AC MDSCs potently suppress T cell proliferation when cultured together in vitro. AC MDSCs also facilitate naïve CD4+ T cells to differentiate into regulatory T cells. In addition, we were able to demonstrate a significant delay in alloislet rejection compared with that by saline-treated control following adjuvant treatment in a MDSC-dependent manner. Furthermore, AC MDSCs produce significantly more interleukin (IL)-10 than saline-treated controls, which we demonstrated to be critical for the increased T cell suppressor function of AC MDSCs as well as the observed protective effect of AC against alloislet rejection. Our data suggest that adjuvant-related therapeutics designed to expand MDSCs could be a useful strategy to prevent transplant rejection and curb the use of toxic immunosuppressive regimens currently used in transplant patients.